Towers and transmission towers are utilized in multiple industries including radio, television, and cellular phone. Towers are also used in the power transmission and wind turbine industries. One type of tower (or structure) is known as a guyed structure or alternatively an additionally guyed structure. In both, guy wires (or guy anchors) are attached when the construction has to withstand strong forces in a certain direction (typically wind). Guy wires assist in maintaining the structure in a vertical position. In a standard arrangement the structures having a main body (mast) which stands on top of a base. The base usually being a concrete structure or slab, or any number of materials able to maintain the loads required. Guy wires then attach to the structure/mast and extend down and away from the mast. The guy wires are fixed securely to the ground via an anchor.
Triangulation is often employed as the means of securing the structures, though any number (1, 2, 3, 4 and more) of guyings are possible to secure a structure. In a triangular setup at least three guy anchors are provided approximately 120 degrees from one another to provide a stable means of keeping the mast vertical. In other embodiments the structure utilizes more than 3 guy anchors either in an array circumferentially around the mast or by attaching at various heights along the mast. Other known structures include H-framed structures (which require addition guying, such as 6, 12 or more guying arrangements), utility poles, signs, billboards, electrical substations, water tanks, turbines, stacks and other structures.
The termed “guyed structure” being a structure whose masts have no independent means of support, relying entirely on guy wires to hold them upright. The term “additional guyed structures” being a structure which needs guy wires for reinforcement and stability. A guyed structure or an additional guyed structure being cheaper than a completely free-standing structure, while withstanding the same force(s). Guying can also allow for an easy upgrade of existing structures. The disadvantages of guying is that it requires more ground space than a free standing structure and that the guy anchors may handicap nearby agriculture. There also exists the danger that the guys could be damaged at their anchors, requiring fencing to keep potential vandals away.
One major problem regarding guyed structure anchors is corrosion of the means securing to the ground. Another problem encountered is the need to strengthen an existing guy anchor to give it more capacity. In a standard setup the anchor is a concrete block buried below grade (underground). Into this concrete block is affixed a guy anchor shaft of varying lengths. This guy anchor shaft originating in the block underground and emerging above ground and adhering to a collar, head or other means of affixing to a wire or cable which then affixes to the mast. This guy anchor shaft being below ground is exposed to water, soil and other contaminants. With the nature of the materials used being typically metal, galvanic corrosion is one concern and as such, grounding spike(s) are often utilized. Corrosion may also be electrolytic in nature. This ongoing corrosion eventually leading to a loss of material from the guy anchor shaft and with the accompanied tensile forces from the strains of the mast, eventually leading to anchor shaft failure. If not remedied, structure failure may follow as a result. In order to avoid structure failure, a means of further securing the guy wire attachment to the foundation (or anchor) is needed.
Owners of the guyed structures utilize a variety of means for remediating the structure to prevent failure, but all have drawbacks due to costs, ease of installation or usefulness of the remediation. Known methods include inspection (ex: visual, electronic or other non-destructive means) of the anchor shafts, installing a new dead man anchor in front of the corroded anchor, installing a new anchor behind the corroded anchor and/or installing a new drilled pier anchor to offset to one side of the corroded anchor. Some of these methods requiring replacement or relocation of the guy wires or anchors or may not be sufficient to withstand the stresses involved. Also known in the art are attempts to create a new (second) concrete anchor above the existing anchor as are described in US Patent Application 2013/0000244, and U.S. Pat. Nos. 8,458,986 and 8,250,817.